1. Field of the Invention
This invention relates to database management systems, and more specifically relates to marking and selecting or filtering of elements in a database management system.
2. Description of Related Art
Computerized databases form a common tool used in connection with computers and networks. Application programs running on computers and network devices utilized databases, which were used to store, manage and retrieve data, especially tables. The application programs required suitable methods to maintain, retrieve and update the stored data. The stored data elements form the actual database where, in case of relational databases, the data entries are in the form of tables arranged in columns and rows.
A database management system (DBMS) was a tool for accessing, editing, storing and querying the database tables. The DBMS used relational algebra to logically connect the entries of the tables.
The user accessed tables of a database by means of the DBMS. The user accessed the tables to enter new data, delete old data, or generate relations between different tables in the database. The DBMS offered the user the option to process the data stored in different tables, e.g., the serial number of components required for a device along with the actual number of components in the stock, and to generate, for example, an order to the manufacturer of the components.
To access the tables in the DBMS, a front-end, a user interface, or a suitably defined data source, e.g. a terminal having a screen, a directory structure containing the tables was provided. In the directory structure, the tables were usually stored in hierarchic orders.
The hierarchic directories of conventional front-ends for a DBMS were structured in catalogs, schemas and tables, at least in tables. The presence of catalogs and schemas depended on the respective DBMS. Usually, a database administer provided access rights to the tables or selected tables for each particular user. In centralized network databases, the number of stored tables, structures, and catalogs was so large that the average user was not able to decide what data should be visible and what data should not be visible.
To select a certain table a user accessed a certain catalog, a certain schema in the catalog, and selected a certain table in this sub-structure. To simplify the access to selected tables, a user selected a filter option for the selected tables. The tables that satisfied the filter operation were displayed and those that did not were hidden. A filter suitable for use for the filter operation is described in U.S. Patent Application Publication No. US2001/0003455 A1, entitled “Method, System and Graphic User Interface for Entering and Editing Filter Conditions For Filtering a Database,” of Dirk Grobler, published on Jun. 14, 2001 and assigned to Sun Microsystems, Inc.
In addition, some front-end programs of a DBMS offered the user the option to mark tables that were on the lowest hierarchic level. The marking was user-specific and so only the user who applied the marks saw the marks.
For example, FIG. 1A depicts a hierarchical directory structure of a conventional user interface of a front end of a database management system. The hierarchical directory structure has containers, e.g., catalog 102, and schemas 122, 124, 126, 128 and a plurality of tables including tables 122_2, 122_4, 122_6, 122_8, 124_2, 124_4, 124_6, 124_8, 126_2, 126_4, 126_6, 126_8, 128_2, 128_4, 128_6, and 128_8. In this example, catalogs were at the highest level of the hierarchical directory structure and tables were at the lowest level of the hierarchical directory structure.
In this example, catalog 102 contains a number N of schemas 122, 124, 126, 128, which are all illustrated. Only catalog 102 is depicted in the directory structure to simplify the figure. Other catalogs may be present but are not shown in this example. In this example, each schema 122, 124, 126, and 128 includes a different plurality of tables, i.e., schema 122 includes tables 122_2, 122_4, 122_6, 122_8; schema 124 includes tables 124_2, 124_4, 124_6, 124_8; schema 126 includes tables 126_2, 126_4, 126_6, 126_8; and schema 128 includes tables 128_2, 128_4, 128_6 and 128_8.
Each of tables 122_2, 122_4, 122_6, 122_8, 124_2, 124_4, 124_6, 124_8, 126_2, 126_4, 126_6, 126_8, 128_2, 128_4, 128_6, and 128_8 had a checkbox that permitted a user to mark the corresponding table. In FIG. 1B, a user has marked tables 122_2, 122_4, 122_6, 122_8, 126_2, 126_6, 128_6 and 128_8.
The front-end of the DBMS typically provided the user a filter to hide all unmarked tables 124_2, 124_4, 124_6, 124_8, 126_4, 126_6, 128_2 and 128_4 in the database hierarchical directory structure of FIG. 1B.
FIG. 1C depicts the hierarchical directory structure of FIG. 1A after the filter to hide all unmarked tables in FIG. 1B has been applied. The filter has filtered the hierarchical directory structure and has hidden all unmarked tables as illustrated in FIG. 1C.
While this mechanism allowed a user to display a hierarchical structure of interest to the user. The user markings could be applied only to the lowest level in the hierarchy. Also, since the markings were user specific, the display of FIG. 1C could not be viewed by another user.
These conventional user markings were static. This met, for example, that if the user-marked the tables as illustrated in FIG. 1B and saved the corresponding filter with those marking, when another user added a new table to schema 122, in which the user wanted to see all tables, the newly entered table was not shown because the new table was not marked by the user. With this method, the marks are static and any newly generated and unmarked tables are hidden and therefore cannot be displayed to the user.